1 Hit of Meth Is Too Much in Pregnancy

July 27, 2005 -- Even one low dose of methamphetamine affects a baby during pregnancy, new research shows.

The "meth" test was done on mice, not people. Nearly 9 million people in the U.S. have tried methamphetamine at some point in their lives, the researchers write in Free Radical Biology and Medicine.

"It's pretty remarkable that a single low dose can have such an effect," says Peter Wells, PharmD, in a news release.

Wells is a University of Toronto pharmacy and pharmacology professor. He and his colleagues gave one low dose of methamphetamine (also called "meth," "speed," "crystal," "Tina," and "ice") to pregnant mice.

The mice's offspring had long-term problems, including muscle coordination. Those problems weren't seen in the offspring of mice that got a saltwater shot with no drugs.

Women are urged by doctors and health experts to take especially good care of themselves during pregnancy. That means steering clear of illegal drugs (as well as tobacco and alcohol) and getting prenatal care.

"We've known for a while that meth abuse during pregnancy is associated with low birth weight, cleft palates, and other malformations," says Wells. "But this is the first research demonstrating that even a single exposure can cause long-term damage."

Babies born to the "meth mice" had muscle coordination problems that lasted at least 12 weeks after birth, write the researchers.

"People usually think the last trimester of pregnancy is when developing brain function is most susceptible to damage. But in this case, the brain is also affected by methamphetamine even in the earlier embryonic period," says Wells.

Adults can also be harmed by meth. The toxic brain effects were different in the adult mice, write the researchers.

Developing babies may be more vulnerable to free radicals, write the researchers. Free radicals are damaging chemicals that can hurt cells' DNA.

The researchers link DNA damage in the baby mice to the single shot of meth given during pregnancy.

Wells' team plans to study the effects of methamphetamine on women and babies, states the news release. Of course, the scientists won't be giving anyone meth. Those studies would only include women who admit using meth while pregnant.

SOURCES: Jeng, W. Free Radical Biology and Medicine, August 2005; vol 39: pp 317-326. News release, University of Toronto.